Reciprocating engines

ABSTRACT

A reciprocating engine is provided having a hollow cylinder and spaced crankshaft with an eccentric cam, a piston slidable in said cylinder with radial clearance, a plurality of spaced annular grooves around the piston circumference, a ring of resin having a low coefficient of friction in each said groove between the piston and cylinder, a connecting rod connected at one end to said crankshaft through a prelubricated anti-friction bearing and at the other end to the piston by a deflectable member capable of angular deflection.

United States Patent Friedman et al.

1 1 May 2,1972

RECIPROCATING ENGINES Inventors: Milton I. Friedman, 2120 Hillholm St;Theodore Kordell, RD. 4, Box l80-D, both of Johnstown, Pa. 15905 Filed:Aug. 28, 1970 Appl.No.: 67,952

U.S. c1 ..92/84, 92 137, 92/187, 92/212, 92/249 Int. Cl ..F16j 1 14Field of Search ..92/84,137, 187,212,216, 92/249, 256; 287/20 P; 123/193P References Cited UNITED STATES PATENTS 2/1885 Nash ..92/187 Xl,450,177 4/1923 l-loupert ..92/84 3,161,185 12/1964 Justinien et al.....92/l87 X 3,375,972 4/1968 Raufeisen ..92/212 X Primary ExaminerMartinP. Schwadron Assistant Examinerlrwin C. Cohen AttarneyBuell, Blenko &Ziesenheim [5 7] ABSTRACT A reciprocating engine is provided having ahollow cylinder and spaced crankshaft with an eccentric cam, a pistonslidable in said cylinder with radial clearance, a plurality of spacedannular grooves around the piston circumference, a ring of resin havinga low coefficient of friction in each said groove between the piston andcylinder, a connecting rod connected at one end to said crankshaftthrough a prelubricated anti-friction bearing and at the other end tothe piston by a defiectable member capable of angular deflection.

8 Claims, 3 Drawing Figures Patented May 2, 1972 3,659,502

INVENTORS Milton l. Friedman 8| Theodore Kordell RECIPROCATING ENGINESThis invention relates to reciprocating engines and particularly toreciprocating devices which move in a straight line and are driven by arotating crank or cam and which require no lubrication. Typical of suchdevices are air compressors, internal combustion engines and the like,which have a reciprocating piston connected to a crankshaft by aconnecting rod.

Reciprocating devices of the type mentioned above have long been knownand used. However, such devices generally require that a constant supplyof oil be delivered to the bearing connecting the connecting rod to thewrist pin in the piston, to the bearing at the opposite end of theconnecting rod on the crankshaft and to the piston surfaces which rideon the cylinder walls. In the past, structures like this, have been aproblem of considerable significance because it required the use of anoil pump and lines to deliver oil to the bearings and to the cylinderwalls. This, of course, is a considerable expense and any failure of oilsupply results in a loss of the bearings and binding of the piston inthe cylinder wall.

There has long been a need for a reciprocating engine which does notrequire continuing lubricating and which eliminates the need for oilsumps, oil pumps and oil lines. There have been proposed reciprocatingengines using prelubricated sealed bearings. However, these arerelatively expensive and are less than satisfactory in many ways. Thisis particularly true of the connection between the connecting rod andpiston where the wrist pin is usually used.

There have been many proposals for reciprocating engine structuresdesigned to eliminate lubrication particularly at the connection betweenthe connecting rod and piston. Typical of such proposals are those ofAllinquant U.S. Pat. No. 3,168,301; Kastler U.S. Pat. No. 2,296,469;Perry U.S. Pat. No. 2,574,934 and Rumsey U.S. Pat. No. 3,451,315. Noneof these structures have met with any significant commercial acceptancebecause of the high wear rate and expense involved in their use.

We have developed a reciprocating engine which eliminates the need forcontinuous lubricating, and which provides in particular a mechanism forconnecting the piston and connecting rod without use of a lubricatedconnection.

Preferably, we provide a piston slidable in a cylinder with radialclearance, a plurality of spaced apart annular grooves around thepiston, a ring of resin having a low coefficient of friction in each ofsaid groves between the piston and cylinder, a crankshaft spaced fromsaid piston, a connecting rod connected at one end to said crankshaft bya prelubricated antifriction type bearing and connected at the other endto the piston by a deflectable member capable of angular deflection.Preferably, the ring of resin is a ring of polytetrafluorethylene. Thedeflectable member is preferably a sheet metal or plastic spring memberfixed along one edge to the end of the connecting rod and along theopposite edge to the interior of the piston, diametrically thereof. Theanti-friction bearings are preferably ball bearings which arepre-lubricated and need no added lubricant during their useful life.

In the foregoing general statement, we have set out certain objects,purposes and advantages of our invention. Other objects, purposes andadvantages will be apparent from a consideration of the followingdescription and the accompanying drawings in which:

FIG. 3 is a side elevational view of a deflectable member used in ourinvention.

Referring to the drawings, we have illustrated an air compressor housing10 including a cylinder 11. A piston 12 having ring grooves 13 ismovable longitudinally within cylinder 11. Rings 14 of Teflon (DuPontspolytetrafluorethylene) are inserted in grooves 13 to bear against theinner wall of cylinder 11. A crankshaft 15 extends through housing 10below the piston 12 and is provided with a crank eccentric 16. Aconnecting rod 17 is connected at one end to eccentric 16 byprelubricated ball bearing 18. The other end of the connecting rod 17 isconnected to one side of a formed sheet 19 of spring steel. The otherside of said sheet of spring steel is connected to a diametrical slot 20in piston 12. i

When the crankshaft is rotated by means of a motor (not shown) theconnecting rod moves vertically as well as from side to side at itsconnection with the crankshaft. This causes the piston 12 to movelongitudinally within the cylinder 11 and the spring steel member 19deflects from side to side in the portion intermediate its connectededges. This deflecting movement provides the necessary articulationbetween the piston and connecting rod and eliminates the need for alubricated bearing. The Teflon rings provide the necessary sealing andlubricating action between the piston and cylinder and eliminates theneed for a lubricant on the cylinder walls.

While we have illustrated and described a presently preferred embodimentof our invention in the foregoing specification, it will be understoodthat the invention may be otherwise embodied within the scope of thefollowing claims.

We claim:

1. In a reciprocating engine having a hollow cylinder and spacedcrankshaft with an eccentric cam, a piston slidable in said cylinderwith radial clearance, a plurality of spaced annular grooves around thepiston circumference, a ring of resin having a low coefficient offriction in each said groove between the piston and cylinder, aconnecting rod, a prelubricated anti-friction bearing at one end of saidconnecting rod connecting the same to said crankshaft and a deflectablemember capable of annular deflection, said deflectable member beingfixed at one edge thereof to said piston and being fixed at an oppositeedge thereof to said connecting rod.

2. A reciprocating engine as claimed in claim 1 wherein the resin ringis polytetrafluorethylene.

3. A reciprocating engine as claimed in claim 1 wherein theanti-friction bearing is a ball bearing.

4. A reciprocating engine as claimed in claim 1 wherein the deflectablemember is a sheet of spring steel.

5. A reciprocating engine as claimed in claim 1 wherein the deflectablemember is a rectangular steel sheet.

6. A piston and connecting rod structure for reciprocating enginescomprising a connecting rod connected at one end to a crankshaft, adeflectable member fixed at the other end of said connecting rod atoneedge of the deflectable member and a piston connected across itsdiameter to the opposite edge of said deflectable member spaced fromsaid other end of said connecting rod whereby said connecting rod andpiston can assume varying angular relationships through the deflec- FIG.1 is a vertical section through an air compressor incorporating ourinvention;

FIG. 2 is a section on the line Il-II of FIG. 1; and

tion of said deflectable member.

7. A piston and connecting rod structure as claimed in claim 6 whereinthe deflectable member is a metal sheet.

8. A piston and connecting rod structure as claimed in claim 6 whereinthe deflectable member is a plastic-resin sheet.

1. In a reciprocating engine having a hollow cylinder and spacedcrankshaft with an eccentric cam, a piston slidable in said cylinderwith radial clearance, a plurality of spaced annular grooves around thepiston circumference, a ring of resin having a low coefficient offriction in each said groove between the piston and cylinder, aconnecting rod, a prelubricated antifriction bearing at one end of saidconnecting rod connecting the same to said crankshaft and a deflectablemember capable of annular deflection, said deflectable member beingfixed at one edge thereof to said piston and being fixed at an oppositeedge thereof to said connecting rod.
 2. A reciprocating engine asclaimed in claim 1 wherein the resin ring is polytetrafluorethylene. 3.A reciprocating engine as claimed in claim 1 wherein the anti-frictionbearing is a ball bearing.
 4. A reciprocating engine as claimed in claim1 wherein the deflectable member is a sheet of spring steel.
 5. Areciprocating engine as claimed in claim 1 wherein the deflectablemember is a rectangular steel sheet.
 6. A piston and connecting rodstructure for reciprocating engines comprising a connecting rodconnected at one end to a crankshaft, a deflectable member fixed at theother end of said connecting rod at one edge of the deflectable memberand a piston connected across its diameter to the opposite edge of saiddeflectable member spaced from said other end of said connecting rodwhereby said connecTing rod and piston can assume varying angularrelationships through the deflection of said deflectable member.
 7. Apiston and connecting rod structure as claimed in claim 6 wherein thedeflectable member is a metal sheet.
 8. A piston and connecting rodstructure as claimed in claim 6 wherein the deflectable member is aplastic resin sheet.